1. Field of the Invention
The present invention relates to hydrodynamic depressors or tuggers for fishing lines used to divert the trailing end of a fishing line and its hook, lure or bait attachments such as to submerge the trailing end of a trolled fishing line and its attachments to a desired depth and/or to offset the course of the tugger from the course of the leading end of the fishing line such as to draw such line end and its attachments into a current.
2. Prior Art
Collins U.S. Pat. No. 3,466,787, issued Sep. 16, 1969, and Zaharis U.S. Pat. No. 3,708,904, issued Jan. 9, 1973 both show depressors for fishing lines, but these patents do not show any provision for offsetting the course of such depressors laterally from the course of the leading end of the fishing line, nor do they have any provision for attracting fish.
Heili U.S. Pat. No. 3,863,382, issued Feb. 4, 1975, shows a fishing line depressor having a bail 14 to which a fishing line is attached and, as shown in FIG. 3 and described at column 4, lines 41 to 46, this bail can be displaced from the solid-line position shown in FIG. 3 to either of the dotted-line positions to cause the diving plane to move to the left or to the right when the depressor is in operation to provide some lateral displacement of the diving plane. Also the leader to the lure or bait can be attached to locations offset from the center of the body to provide some lateral displacement.
The depressors of the Collins and Zaharis patents do not have any provision for stabilizing the depressor to cause it to maintain a steady course.
Louthan U.S. Pat. No. 2,247,583, issued Jul. 1, 1941, and Louthan U.S. Pat. No. 2,273,209, issued Feb. 17, 1942 show fishing line depressors having ovate or egg-shaped plate bodies which have rudders intended to hold the depressor on a straight course so that it will not wobble from side to side.
The Shaw U.S. Pat. No. 3,831,308, issued Aug. 27, 1974, shows a fishing line depressor having two pairs of wings projecting laterally oppositely from a body, one pair being relatively large forward wings and the other pair being relatively small rearward wings. As shown in FIGS. 2 and 3, the larger wings are set both at a dihedral angle and at a negative angle of incidence, while the smaller wings do not have a dihedral angle but are set at a negative angle of incidence to cause the depressor to descend when the fishing line 10 is attached as shown in FIG. 7. When the fishing line is reversed to the position shown in FIG. 8, the angles of incidence of the wings are positive to effect surfacing of the depressor as it is moved through the water.
In Holstein U.S. Pat. No. 4,161,841, issued Jul. 24, 1979, a fishing line depressor is shown which has a wing with its forward tips bent upward and its rearward tips bent downward to form spoilers that are stated to cause the depressor ultimately to rise and fall, whereas a plate 27 on the front end of the device in conjunction with a rear downwardly-turned spoiler causes the device to oscillate from right to left.